的Rails 3：如何使在MySQL超過3個表（附：通過模型）聯接

Question

ingredient.rb：

class Ingredient < ActiveRecord::Base 
    has_many :recipes, :through => :ingredients_with_quantities 
    has_many :ingredients_with_quantities 

ingredient_with_quantity.rb：

class IngredientWithQuantity < ActiveRecord::Base 
    belongs_to :recipe 
    belongs_to :ingredient 

recipe.rb：

class Recipe < ActiveRecord::Base 
    has_many :ingredients, :through => :ingredients_with_quantities 
    has_many :ingredients_with_quantities 

我想做一個查詢，獲取所有包含特定成分名稱的食譜。

嘗試這樣的查詢：

Recipe.find(:all, :include => {:ingredients_with_quantities => :ingredients}, :conditions => "ingredients.name = 'ingredient1'") 

但我得到這個錯誤：

NameError: uninitialized constant Recipe::IngredientsWithQuantity 

有人能告訴我什麼是錯的查詢？

我可以做一個全成查詢SQL中使用：

SELECT r . * FROM recipes r, ingredient_with_quantities iq, ingredients i 
WHERE i.name = "ingredient1" 
AND iq.recipe_id = r.id 
AND iq.ingredient_id = i.id 

請問這個查詢看起來滑軌用ActiveRecord？

感謝您的幫助！

Answer 1

這是:ingredient_with_quantities而非:ingredients_with_quantities（你把一個 「S」 ingredient後）